In
Brief:- Engines and their horsepower. The ratio of cc to hp varies by the cu.in.
or cu.cm., rpm, tune and
if blown, turbocharged or supercharged but is about 1 cu.in per hp for a modern,
general purpose vehicle engine

Many
people have asked for a relationship between horsepower and cc or how
many cc in a hp.

The short answer is about 15 to 17cc = 1 hp or about 1 cu.in. = 1 bhp
for an ordinary, basic car.

The full answer is complex - the power output of an engine depends on
the state of tune as well as size, and the definition of horsepower must
be considered, brake horsepower ( bhp ) or shaft horsepower ( shp ), and
is not covered here.

Horsepower can be increased by engine tuning, more
volatile fuel, supercharging or exhaust turbo boosting.